Design of three-Electrode Immersion Electrostatic Lens

Abstract

The present work includes acomputerized investigation has been carried out on the design of three electrodes electrostatic lens with low aberration used in the solution of Laplace equation for determine the axial potential distribution. The paraxial –ray equation was solved to obtain the trajectory of particles that satisfy the suggested potential function. The electrode shape of the electrostatic lens was the determined from the solution of Laplace equation and plotted in two dimensions. The results showed low values of spherical and chromatic aberrations, which are considered as good criteria for good design